• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.4
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• pp.672-678
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• 2002

Oxidative stress contributes to cellular injury following clinical and experimental ischemia/reperfusion scenarios. Oxidative injury can induce cellular and nuclear damages that result in apoptotic cell death. We tested the hypothesis that the catechin flavonoid of (-)epigallocatechin gallate, a green tea polyphenol, inhibits hydrogen peroxide ($H_2O$$_2$)-induced apoptosis in human umbilical vein endothelial cells. The effect of apigenin, a flavone found in citrus fruits, on apoptosis parameters was also examined. A 30 min pulse treatment with 0.25 mM $H_2O$$_2$ decreased endothelial cell viability within 24 hrs by > 30% ; this was associated with nuclear condensation and biochemical DNA damage consistent with programmed cell death. In the 0.25 mM $H_2O$$_2$apoptosis model, 50${\mu}{\textrm}{m}$ (-)epigallocatechin gallate markedly increased cell viability with a reduction in the nuclear condensation and DNA fragmentation. In contrast, equimicromolar apigenin increased cell loss with intense DNA laddering, positive nick-end labeling and Hoechst 33258 staining. Thus, polyphenolic (-)epigallocatechin gallate, but not apigenin flavone, qualify as an antioxidant in apoptosis models caused by oxidative stress. Further work is necessary for elucidating the anti-apoptotic mechanisms of polyphenolic catechins.

• Journal of Microbiology and Biotechnology
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• v.27 no.1
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• pp.72-76
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• 2017

Detection of exon 19 deletion mutation in the epidermal growth factor receptor (EGFR) gene, which results in increased and sustained phosphorylation of EGFR, is important for diagnosis and treatment guidelines in non-small-cell lung cancer. Here, we have developed a simple and convenient detection system using the interaction between G-quadruplex and fluorophore thioflavin T (ThT) for discriminating EGFR exon 19 deletion mutant DNA from wild type without a label and quencher. In the presence of exon 19 deletion mutant DNA, the probe DNAs annealed to the target sequences were transformed into G-quadruplex structure. Subsequent intercalation of ThT into the G-quadruplex resulted in a light-up fluorescence signal, which reflects the amount of mutant DNA. Due to stark differences in fluorescence intensity between mutant and wild-type DNA, we suggest that the induced G-quadruplex structure in the probe DNA can report the presence of cancer-causing deletion mutant DNAs with high sensitivity.

• Nutrition Research and Practice
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• v.6 no.5
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• pp.389-395
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• 2012

The study elucidated carbohydrase inhibition, anti-cancerous, free radical scavenging properties and also investigated the DNA and protein protection abilities of methanolic root extract of Rumex crispus (RERC). For this purpose, pulverized roots of Rumex crispus was extracted in methanol (80% and absolute conc.) for 3 hrs for $60^{\circ}C$ and filtered and evaporated with vacuum rotary evaporator. RERC showed high phenolic content ($211{\mu}g$/GAE equivalent) and strong 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ($IC_{50}$ = 42.86 (absolute methanol) and $36.91{\mu}g/mL$ (80% methanolic extract)) and reduced power ability. Furthermore, RERC exhibited significant protective ability in $H_2O_2/Fe^{3+}$/ascorbic acid-induced protein or DNA damage and percentage inhibition of the HT-29 cell growth rate following 80% methanolic RERC exposure at $400{\mu}g/mL$ was observed to be highest ($10.2%{\pm}1.03$). Moreover, methanolic RERC inhibited ${\alpha}$-glucosidase and amylase effectively and significantly (P < 0.05). Conclusively, RERC could be considered as potent carbohydrase inhibitor, anti-cancerous and anti-oxidant.

• Journal of Nutrition and Health
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• v.36 no.3
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• pp.255-261
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• 2003

Food irradiation has been steadily increasing in many countries in line with increasing international trade and concerns about naturally occurring harmful contaminants in food. Although irradiation provides an excellent safeguard for the consumer by destroying almost 100% of harmful bacteria, it is necessary to ensure the safety of irradiated foods. This study was performed to investigate the effect of an irradiated diet on lipid peroxidation in the plasma, liver, small intestinal mucosa, and lymphocyte DNA damage in mice. Eight-week old ICR mice were assigned to two groups to receive either non-irradiated or irradiated (10 kGy) diets containing 20.38% fish powder and 6.06% sesame seeds for 4 weeks. The resulting changes in the degrees of lipid peroxidation were evaluated based on the level of plasma and liver thiobarbituric acid reactive substance (TBARS), transmission electron micrograph of jejunal mucosa, and free radical-induced oxidative DNA damage in lymphocytes, as measured by alkaline comet assay (single cell gel electrophoresis). The peroxide values of the gamma irradiated diet were measured every week, and the sample for comet assay was taken at the end of the four week experimental period. There was no significant difference in food efficiency ratio between the two groups. The peroxide values of the diet were immediately increased to 35.5% after gamma irradiation and kept on increasing during storage. After 4 weeks, no differences in tissue or plasma TBARS value were observed between the two groups, but epithelial cells of jejumum showed osmiophillic laminated membranous structures, considered as myelin figures,. The oxidative DNA damage expressed as tail moment (TM) increased 30% in the blood lymphocytes of the mice fed the irradiated diet. In conclusion, the comet assay sensitively detected differences in lymphocyte DNA damage after feeding with the irradiated diet for 4 weeks. However, in order to ensure the safety of irradiated foods, it would be more useful to conduct a long-term feeding regimen using an irradiated diet and examine the level of lipid peroxidation and the state of oxidative stress in a greater range of organs.

• Microbiology and Biotechnology Letters
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• v.14 no.6
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• pp.455-460
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• 1986

Dane particle was prepared from the plasma of chronic HBsAg carrier with high levels of HBsAg activity. DNA extracted front Dane particle core after a DNA polymerase reaction with $\alpha$-($^{32}$P) dNTP, was identified as HBV DNA by liquid scintillation counter and agarose gel electrophoresis-G.M. counting. To produce Hepatitis B surface antigen for use as a vaccine against Hepatitis B virus infection, yeast strains harboring recombinant plasmid with Apase promoter was used. Recombinant plasmid was construced from pHBV 130 and pAN 82, transformed into E coli, and then transferred into yeast strains. HBsAg was produced by derepression in Burkholder minimal medium with controlled inorganic phosphate concentration. The kinetics of HBsAg production was also investigated. Total HBsAg activity increased rapidly between 3 and 6 hours after transfer to phosphate-free medium and reached a maximum at around 9th hour. The transfer into phosphate-free medium after 6 hours in high phosphate cell growth medium gave maximum activity.

• Korean Journal of Microbiology
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• v.5 no.2
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• pp.61-68
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• 1967

In the process of the incorporation of orthophsphate into protein and other cell constituents, the role of inorganic polyphosphate and RNA-polyphosphate complex and the correlation between them were pursued by analyzing the contents of $^{32}P$ and total P in various fractions of Chlorella cells, which had been uniformly labeled with $^{32}P$ before the inoculation in a normal "cold" medium or P-free medium during the culture. The effects of ionizing radiation and various micronutritional-element deficiencies on the phosphate incorporation into, and biosynthesis of, protein and other introgenus compounds in the cells were also observed. When the uniformly $^{32}P$-labeled algae were grown in a normal "cold" medium the contents of $^{32}$ P in the fractions of protein, DNA and RNA-polyphosphate complex increased, but those in the fraction of acid-insoluble polyphosphate decreased. On the other hand, amount of $^{32}P$in the fraction of RNA was almost unchanged in spite of rapid increase of the total P. In the growing period of $^{32}P$-labeled algae in a P-free medium, amounts of $^{32}P$ in the fractions of DNA, protein and lipid increased, while those in the fractions of RNA-polyphosphate and inorganic polyphosphates decreased. When the algal cells were irradiated with about 70, 000r of gamma-rays before the inoculation in the medium, amounts of phosphate in the fractions of DNA, RNA, nucleotides and protein decreased during the culture, compared with those of the control. However, the phosphate content in the fraction of acid-insoluble polyphosphate of the irradiated cells increased than those of the control. In the growing period of the algae in a Mo-free, medium, amounts of acid-soluble total phosphate and nucleotides of the cells increased, while the amounts of residual protein and RNA decresed compared with those of the normal cells. Amounts of alkali-labile protein and phospholipid of the cells grown in a B-free medium decreased, whereas amount of phosphate in acid-soluble fraction increased compared with the control. In general, the contents of protein and RNA in each microelement deficient cells decreased more or less, compared with those in the normal cells.in the normal cells.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.28 no.1
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• pp.71-79
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• 2002

In the aged skin especially in the face and eyelid, deep and slight wrinkles are one of the remarkable phenomena of aging and the cause of wrinkle is various. Among the cause of wrinkles an oxidative stress plays an important roles in wrinkle formation process. It caused the lipid peroxidation of cell membrane, the increase of the MMPs(MatrixMetalloProteinase) gene expression and cellular DNA damage. These ROS induced materials may cause the degradation of collagen matrix system in the dermis and cause the formation of skin wrinkle. So, it is very important for protecting skin wrinkle formation to regulate ROS activity. In this study, we developed one active ingredient having multi functional activities such as activation of collagen synthesis, inhibition of MMPs activity, lipid peroxidation and free radical scavenging activity and inhibition of free radical induced DNA damage in vitro. Pericarpium castaneae extracts showed collagen synthesis increase in Normal Human Fibroblast and the inhibition of elastase activity (IC$\_$50/ of Elastase: 43.9$\mu\textrm{g}$/㎖). It showed also anti-oxidative activity (IC$\_$50/ : 48$\mu\textrm{g}$/㎖) and free radical scavenging activity(IC$\_$50/: 7.6$\mu\textrm{g}$/㎖). Conclusively, Pericarpium castaneae extracts may be used as an ingredient for new anti-wrinkle cosmetics.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.4
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• pp.319-324
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• 2006

Although the sera used in animal cell culture media provide the macromolecules, nutrients, hormones, and growth factors necessary to support cell growth, it could also be an obstacle to the production of recombinant proteins in animal cell culture systems used in many sectors of the biotechnology industry. For this reason, many research groups, including our laboratory, have been trying to develop serum-free media (SFM) or serum-supplemented media (SSM) for special or multi-purpose cell lines. The Chinese hamster ovary (CHO) cell, for example, is frequently used to produce proteins and is especially valuable in the large-scale production of pharmaceutically important proteins, yet information about its genome is lacking. Also, SFMs have only been evaluated by comparing growth patterns for cells grown in SFMs with those grown in SSM or by measuring the titer of the target protein obtained from cells grown in each type of medium. These are not reliable methods of obtaining the type of information needed to determine whether an SFM should be replaced with an SSM. We carried out a cDNA microarray analysis to evaluate MED-3, an SFM developed in our laboratory, as a CHO culture medium When CHO cells were cultured in MED-3 instead of an SSM, several genes associated with cell growth were down-regulated, although this change diminished over time. We found that the insulin-like growth factor (IGF) gene was representative of the proteins that were down-regulated in cells cultured in MED-3. When several key supplements - including insulin, transferrin, ethanolamine, and selenium - were removed from MED-3, the IGF expression was consistently down- regulated and cell growth decreased proportionately. Based on these results, we concluded that when an SFM is used as a culture medium, it is important to supplement it with substances that can help the cells maintain a high level of IGF expression. The data presented in this study, therefore, might provide useful information for the design and development of SFM or SSM, as well as for the design of genome-based studies of CHO cells to determine how they can be used optimally for protein production in pharmaceutical and biomedical research.

• Journal of Life Science
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• v.21 no.12
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• pp.1698-1704
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• 2011

In this study, we evaluated the protective effects of ethanol extracts from Dendranthema indicum on cell and DNA damages induced by oxidative stress. Antioxidant activities of D. indicum extracts are higher than scavenging activities of DPPH free radical and hydroxyl radical by 92.8% and 73.8%, respectively, and higher than ferrous iron chelating effects by 59.4%. D. indicum extracts showed a protective effect on oxidative cell damage by inhibiting lipid peroxidation by 90.3% in the control group, and inhibiting expression level of p21 protein by 79.6% for the control group. This means D. indicum extracts have a great protective effect against oxidative stress. DNA fragmentation inhibition in D. indicum extracts were 89.6% for the control group, which makes the movement of DNA tail reduced, and phosphorylation of H2AX was 20.2% of the radical experiment group. This means that D. indicum extracts effectively inhibit DNA fragmentation and H2AX phosphorylation. Taken together, we suggest that ethanol extract from D. indicum has a role as a useful chemopreventor against oxidative damage.

• Korean Journal of Environmental Biology
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• v.27 no.2
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• pp.230-236
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• 2009

An extract of Allomyrina dichotoma larva (ADL), one of the insects used most frequently in traditional Chinese medicine for the treatment of liver diseases such as hepatocirrhosis and hepatofibrosis, was assessed for antioxidant bioactivity in this study. In the current work, we have investigated the protective effects of ADL extracts on tert-butyl hydroperoxide (t-BHP)-induced hepatotoxicity in cultured hepa1c1c7 cells and in the mouse liver. The treatment of the hepa1c1c7 cells with ADL extracts induced a significant reduction of t-BHP-induced oxidative injuries, as determined by cell cytotoxicity, lipid peroxidation (LPO) and reactive oxygen species contents, in a dose-dependent manner. Moreover, ADL extracts evidenced a protective effect against t-BHPinduced oxidative DNA damage, as revealed by the results of the Comet assay in hepa1c1c7 cells. ADL extracts also protected against hydroxyl radical-induced 2-deoxy-d-ribose degradation by ferric ion-nitrilotriacetic acid and $H_2O_2$. In addition, ADL extracts were shown to be able to quench 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. Our in vivo study revealed that ADL extracts pretreatment applied prior to t-BHP administration significantly prevented an increase in the serum levels of hepatic enzyme markers and reduced LPO in the mouse liver in a dose-dependent manner. Taken together, these results suggest that the protective effects of ADL extracts against t-BHP-induced hepatotoxicity may be attributable, at least in part, to its ability to scavenge free oxygen radicals, and to protect against DNA damage due to oxidative stress.